Monday, at about 8 p.m., nearly 20 police cars swarmed to a Treme corner, breaking up a memorial procession and taking away two well-known neighborhood musicians in handcuffs.

The brothers, snare drummer Derrick Tabb and trombonist Glen David Andrews, were in a group of two dozen musicians playing a spontaneous parade for tuba player Kerwin James, who died last week of complications from a stroke he had suffered after Hurricane Katrina.

The confrontation spurred cries in the neighborhood about the over-reaction and disproportionate enforcement by police, who had often turned a blind eye to the traditional memorial ceremonies. Still others say the incident is a sign of a greater attack on the cultural history of the old city neighborhood by well-heeled newcomers attracted to Treme by the very history they seem to threaten.

That scene, complete with Andrews, Tabb and Wendell Pierce's Antoine Batiste, opens season three of Treme, which debuts Sunday night on HBO. Season two highlighted the corrupt culture of the New Orleans Police Department after Hurricane Katrina with its Abreu storyline, and season three explores it further. It touches series regulars and a new character, L..P. Everett (Chris Coy), modeled on writer A.C. Thompson, who investigated police violence on Algiers Point after the storm including the murder of Henry Glover. Coy is the new face in the bottom, right-hand corner of the poster promoting the start of the new season, and for him and others in the cast, life in New Orleans isn't manic and desperate like it was in 2006, but it's not easy.

Producer Eric Overmyer spent the last few weeks in New York doing press with Producer David Simon to promote the upcoming season, and when asked about season two, he struggles for a moment. That was shot almost two years ago, so he has to pause to remember what happened. "I know we killed Steve Earle," he says. The street musician he played, Harley Watt, wasn't created with the idea in mind that he'd be killed. After a number of episodes had been shot for season two, the writing team reconvened to develop stories for the back half of the season. "We started to say, 'This season is about the return of violence and crime to the city. Who do we kill?' We weren't quite ready to kill off any of the regulars, and David said, 'Well, probably Harley." It made sense - a street musician, he's out and about all the time and times are dangerous. And it had the upside of affecting Annie very deeply. Steve Earle saw the narrative necessity but he was sorry about it. He was enjoying himself on the show." Harley's death didn't mark the end of work with Treme, though. He wrote songs for the season including, "Is That All You've Got," the song that gave the poster its tag line.

Season three builds on the strengths of the previous two seasons as the show makes palpable the drama of living with real life stakes. That has always been its calling card, but it does so with few forced moments this season, perhaps because 2007 was far enough after Katrina that we were starting to evolve from recovery into building lives in a post-Katrina world, or maybe it's because the show's become better at doing what it does.

"We were learning on the job in the first season how to tell the story and what the show was," Overmyer says. "I think the show is sui generis. It's a fictional show that has real people in it. It references real events and sometimes try to recreate them and uses music and cooking as real as we can, and I can't recall that there's ever been a show like this before."

It's also a very personal show, and that manifests itself in ways that don't happen in other shows. The music isn't only an essential part of the fabric of show; it's one of the priorities that has to be accounted for. John Mooney and The Soul Rebels never played together in real life as they did in season one's finale, but New Orleans being New Orleans, they could have, and by the time of shooting, The Soul Rebels had played with roots rock artists the Honey Island Swamp Band. It was a musical moment David Simon created because he thought it would be compelling, and he was right. Overmyer defends similar liberties taken with the subdudes in the season two premiere. I've written elsewhere that it was unlikely in 2006 that the subdudes would have been touring with an opening band, much less Annie T (Lucia Micarelli), a street musician without a band, an audience and original material.

"I'm willing to bend credibility to get Annie onstage with the subdudes," Overmyer says.."The musical moment outweighs the question, 'Would she really be onstage with the subdudes?'"

At press time, the production has yet to receive word as to whether or not it will get a fourth and final season. If there is a final season, it would shoot during the fall as usual, so shooting on season four would take place while season three is airing.

"If it goes forward, we have to get started right away," he says. At this point, they're two or three weeks behind schedule. If everything does work out, everything will be a little more pressed and maybe starting shooting a week or two later, but we're not terribly behind."

The decision by HBO to move Treme and Boardwalk Empire into the fall will likely affect their ratings as they go up against Sunday night football, but the change had the upside of giving the show additional time for post-production work. "We were able to finish the whole 10 episodes without the distraction of still being in production," Overmyer says.